I am currently connecting to an Access Database from Tableau. Within this Access database it has a flag in order to connect two tables together. I was curious if I could mimic this behavior in the Data connection in Tableau?

To give a very simplistic view of the problem here's a picture of some ID's the DB uses to connect the tables:

The Green columns are the same in 90% of the scenarios (Or when Destination Type is 3... which is 90% of the time!) However as you can see this DestinationID can be different based off the type. When this type is 1 the second green column becomes the same as the teal column. Can I connect data in a way like this in Tableau?

IF Dest Type = 3

THEN DestinationID = GSiteID

ELSE DestinationID = WSiteID (WSite)

END

The above would be a nice way of doing it, if something like this is possible when connecting two tables together in the data source.

This sample is from a full data set that I have vastly simplified. I am hoping that I might be able to connect the set as I have said in the original post. However the data came from a large connection of several tables within the same database. The green is the original connection that is breaking because in certain scenarios as shown the value is actually equal to the teal instead of the green. Which is why this super simple table is the same up until the nulls. And as you can see the nulls come into play when the Dest Type is 1 instead of 3.

So again to reiterate: Can you connect one Table to two different Tables based off of a value from the first table to flag which table to connect from one ID to one of two IDS (For the two corresponding Tables)?

Here is a picture of how the Tables are set up. GSiteID is in Table B. DestinationID and Dest Type is in Table A. And WSiteID (WSite) is in Table C.

So could you connect A to B through DestinationID -> GSite ID when Dest Type is 3 and A to C when Dest Type is 1.

Hopefully that will help clear up the logic, but I get it is a very abstracted concept.